The invention relates to a method for the manufacture of homogenous, gelled milk products such as custards, creams, ice creams, candies and the like which have excellent shelf life.
In the production of cheese, considerable by-products remain which at present are either unusable, or usable at best only as supplements for animal feed. Presently available milk products have limited shelf-storage or usable life. It is one objective of the present invention to make use of such milk and cheese by-products for producing edible gelled milk products which have high nutritive value, and which may economically be produced and which have long storage life.
Two of the presently available by-products are (1) a sol of seroprotein derived from sweet lactoserum and (2) ultrafiltrates of whole or sweet skimmed milk containing lactose. The sol of seroprotein is prepared by subjecting the sweet lactoserum of pH, preferably higher than 5.8 and lower than 7.0 to ultrafiltration, reverse osmosis, dialysis, electrodialysis, etc, such techniques being known in the art. The sweet lactoserum from which the sol of seroprotein is derived is obtained, for example, as one of the components resulting from cheese making processes. Typically one starts with milk and adds rennet thereto. The rennet causes the milk to coagulate to a solid portion, (commonly known as "curd"), which for the most part represents the casein portion of the milk and a liquid portion which contains water, lactose, inorganic salts and soluble seroproteins. In the industry this liquid portion is generally known as "whey". As heretofore mentioned the sweet lactoserum is then subjected to, for example, ultrafiltration by utilization of appropriately sized filter screens and/or diaphragms thus resulting in a separation of the lactose and inorganic salts from the seroproteins sol. The lactose-inorganic salt fraction, sometimes called the "ultrafiltrate" is subsequently hydrolyzed to a degree of between about 75-95 percent lactose completion. According to this invention such hydrolyzed lactose may be used as the glucide, or it may be used with saccharose. Lactose when hydrolyzed converts to a glucose and galactose which have a sweet taste, as compared to the blend or non-sweet taste of the unhydrolyzed product.
The present invention enables commercial use of the aforementioned by-products in the manufacture of nutritionally edible products in gelled form as more fully hereinafter described.